The present invention relates to a digital camera and a document processing system using the digital camera, and more particularly, to a digital camera for reading an original document and performing an optical character recognition (OCR) process, and a document processing system using the digital camera.
In a case of reading a document printed on a sheet of paper or the like and converting the read data into text data to be stored in a storage, the document is first read as image data and the read image data is converted to text data by the OCR process or the like. To reproduce the document, the text data is transferred to a printer and outputted. Having a document as text data is advantageous compared to having the document as image data, in terms of the reduced amount of data to be stored, readiness of data handling, improved quality in the outputted image and so on.
To read the document as image data, a flat-bed scanner, a sheet-feed scanner, or a handy scanner or the like have conventionally been used.
Since small-sized and inexpensive digital cameras have recently become popular, the digital camera can be used as document reading means. This facilitates obtaining a document as image data without requiring a desk-top-oriented facility.
However, using a digital camera as document reading means raises the following problems.
(1) Difficult to assure resolution necessary for the optical character recognition (OCR) process
To perform the normal OCR process, a resolution of about 200 dpi for English font and about 300 dpi for Japanese font are necessary. For instance, in order to read a sheet of print paper having the size A4 (210 mm.times.297 mm) at 300 dpi, the converted data size is approximately equal to 2400.times.3300 pixels, assuming that the paper size is about 8.times.11 inches. However, a digital camera of the generally-used type, comprising a CCD having about 1200.times.1000 pixels, is unable to assure data necessary for the OCR process.
(2) Necessity to correct distortion and perspective of an obtained image
Since an image is sensed by a camera device, the sensed image does not always have as high precision as obtained by other reading means (flat-bed scanner, sheet-feed scanner or the like), which can perform image sensing while an image is precisely facing the reading means. Therefore, a correction process is necessary.